What's the best way to animate a curtain opening?

Hey guys, I’m trying to figure this out, and I’m actually getting paid to animate this. But I’m having a lot of trouble. You know the theater curtains? Red, heavy velvety curtains?


Well, my “client” (:D) wants a set of curtains pulled as if with a draw-string sorta thing. So they’re opening from the sides, not the top. What’s the best way to do this?

My first instinct was to do a little vertex keying in conjunction with softbodies, but that did not work very well. Then I tried using a hook, but that doesn’t affect the softbodies at all. Now I’m sorta stumped.

Any ideas?

Thanks a lot.


How about shape keys on a softbody? One key for open, one for closed. You’d probably have to use goal weights so the top and stationary side don’t wave too much.

Edit: Armatures might give you more control over the curtain movement.

Um, perhaps hooks and softbody?

Eep! Well, I tried all three of those methods- shape keys, armatures, and hooks. They’re all extremely difficult to control. Shape keys seem to be the best option right now but I still can’t get them to work well with the softbody simulation.

At the moment I can’t get hooks working at all. Any other ideas?


Sorry, I didn’t see vertex-keying in your original post. What don’t you like when you’re using them?


To get hooks to work with softbodies, make sure they are higher up the list of modifiers in F9.

[B]Is this similar to what you want(minus details; it’s just the idea)? :

If so…[/B][/B][B][B] http://s10.quicksharing.com/v/1057965/Curtains.blend.html

Hope it helps…

Thanks guys!

That’s okay - what I didn’t like was the fact that just two shape keys weren’t nearly good enough. It looked too much like the curtains were just being pushed from one position to another, and not pulled realistically and gradually from the middle outward.

In real life, the middle would start to pinch and as the ropes were drawn tighter, successive folds would come together until they were drawn all the way. With vertex keys, all the folds in the curtain squash together at one time, like an accordion.

The only way to make that look behave properly, it seems, is to animate it by hand, but I’m looking for an easier way. I don’t want to have to set like 50 vertex keys!

Actually, I’ve found that hooks only work when they’re AFTER the softbodies in the modifier stack. Of course they don’t produce the results I’m looking for, but when I move them above it looks like the softbody system just ignores it. (Although maybe it’s having trouble refreshing or something - does it work on your system?)

Yeah, what I’m looking for is similar, but this guy tells me that the commercial this is going to be for will be aired on TV, so it’s got to look really good. My problem is that I can’t get it to look realistic enough.

Thanks for uploading those files for me though!!


Have you tried lattice?

Maybe try an armature with a bone for each pleat and rotate the first one and key it, then 2nd and so on so they progressively fold like in real life…Yeah, I’m stuck on armatures, but it seems relatively simple, pending pleat number(but I really don’t know anything)…

Here’s a better example of my previous post’s idea, though I didn’t do the ‘rotate each pleat individual for realism’ bit, and I didn’t tweak vertex groups or softbodies(blah, blah). With all this, why post it then? 'Cause I did it and I feel like it:D


I recently did this just using armatures. It was a quick-n-dirty, but since the curtains weren’t on the screen for too long, I could get away with it. The key (for me) was setting up rotational constraints on a series of chains leading away from the pulled edge.

How long is this going to be on-screen? Can you truck the camera in as the curtain pulls aside? That way you get the motion of the curtain, an interesting shot, and you don’t have to worry about some of the details of the curtain animation.

I’m getting surprisingly decent results with a highly damped softbody and a couple of empties with Wind force fields moving with the edge of the curtain. With the right falloff, the force fields make that nice gradual pleating as they move.

EDIT: Link removed due to virus warnings

Thanks so much, guys! I think you have some good ideas. I’m about to try your armature idea, Normal - that sounds promising. Also, your curtain looks pretty good!

Fweeb, unfortunately the curtains will remain onscreen for like 20 seconds after they’ve been opened. So they kinda have to settle and be fairly realistic. How did you set up your armature system? I’ll post screencaps of what I’m trying because I’m not sure its what you or Normal meant.

CD38- Wind! That’s something I haven’t considered. I shall try that. Do you have an animation of that?

grafix - Ah, good thought as well - I haven’t tried lattices yet. Thanks!


If they’re looking for ultra-realistic drapes, what’s the point of doing it on a computer? Why don’t they just film some real drapes ? :confused:

@colin: I have a simple animation of the wind effect and will upload when I’m on a faster connection in the morning. Can anyone recommend a halfway decent site?

@mike: I was wondering the same thing. There must be big drapes all over the place. But this is a fun challenge.

4shared.com seems pretty good, not too obtrusive with the ads.

Fun challenge for us, but unless there’s going to be something very unrealistic mixed with the drapes (and even then maybe compositing ???) I don’t get why the director/client wants perfectly realistic CG drapes ? :confused:


Here is animation of the curtain being pushed aside by wind-empties. It could use some tweaking, especially to straighten out the bottom part but I think it looks OK.

I’d composite a real curtain too, but the problem might be finding a green-screen tall enough to matte the moving edge!

Wow are you really making an animation for a commercial. I wish I was as good as you. I would really like to see an update of the cutains!:slight_smile:

this is probably too late to be useful to the original poster, however i did something very similar to this a couple years back. i found lattices gave excellent results. much easier to manipulate than shape keys for this kind of thing. i was working on max at the time, but i assume blender would yield similar results.

Try softbodies with self-collision and a deflector object to push curtain back. You’ll need the latest build.